VOLTAGE-CONTROLLED SPECTRAL SEPARATION OF LIGHT WITH LIQUID CRYSTALS

• US 3,758,195 A
• Filed: 04/10/1972
• Issued: 09/11/1973
• Est. Priority Date: 04/10/1972
• Status: Expired due to Term

• Current Assignee: Clarence L. Hedman Jr, Karl-Dieter S. Myrenne, Perry H. Vartanian Jr
• Original Assignee: Clarence L. Hedman Jr, Karl-Dieter S. Myrenne, Perry H. Vartanian Jr
• Inventors: Hedman, Clarence L. Jr., Myrenne, Karl-Dieter S., Vartanian, Perry H. Jr.
• Primary Examiner(s): Bauer, Edward S.
• Application Number:
  US05/242,709
• Time in Patent Office: 519 Days
• Field of Search: 350/16LC,162R,168 340/324R,336 356/100
• US Class Current: 349/33
• CPC Class Codes: G02F 1/137 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
• CPC Class Codes: G02F 1/23 for the control of the colour G02F1/03 - G02F1/21 take precedence
• CPC Class Codes: G02F 1/292 by controlled diffraction or phased-array beam steering controlled diffraction for optical switching G02F1/31
• CPC Class Codes: G02F 2203/22 diffractive
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters

Abstract

Light of different colors is produced by using as a '"'"''"'"''"'"''"'"'diffraction grating'"'"''"'"''"'"''"'"' a cell containing a liquid crystal material, with selectively variable fields being applied across the cell to present the different colors at a viewing station. Application is made to monochromators, symbol displays, and other devices.

Claims

2. The combination defined in claim 1, wherein said coatings comprise a plurality of ordinal displays with a said symbol coating in each order consisting of a plurality of segments, each segment having a lead selectably connectible in circuit with said source of potential.

3. The combination of claim 2, wherein there are two sources having first and second potentials, and further including a two-position control operable to provide said first potential to said symbol coatings when said control is in one of said two positions and to provide said second potential to said symbol coatings when said control is in the other of said two positions, said first and second potentials causing said symbol forms to be presented at said viewing station in corresponding different colors.

4. The combination of claim 3, wherein said first potential causes display in a first anomalous dispersion band and said second potential causes display in a second anomalous dispersion band.

5. The combination of claim 3, wherein said sources of potential comprise alternating current sources, the frequency of said current being between 10 Hz and 1000 Hz.

6. The combination of claim 3, wherein said coatings are on opposed ones of said cell walls, said walls being spaced apart less than 25 microns.

7. The combination of claim 6, wherein said mesomorphic material has a nematic mesophase.

8. The combination of claim 7, wherein said nematic mesomorphic material comprises an isomer of p Butyl-p'"'"''"'"' methoxy azoxy benzene.

9. The combination of claim 7, wherein said nematic mesomorphic material comprises a mixture of N-(p Methoxybenzylidine)-p n-butylaniline and N-(p Ethoxybenzylidine)-p n-butylaniline.